Multi-drum coilers and un-coilers have been proposed heretofore to ensure continuity of operation, i.e., to shorten the idle time, in winding or unwinding rolled materials in a rolling mill. The body of such a conventional device has a plurality of winding drum shafts and is rotatably supported. The body is revolved in a circle while one of the drum shafts is being driven for winding or unwinding, in order to exchange the drum shaft in one specific position for another. One example of this kind of device is shown in FIG. 1, where the body 2 of the machine has two winding drum shafts 1a and 1b which are rotated to directly wind or unwind rolled material and which are supported in a symmetrical relation with respect to the central axis of the body. The end of the body 2 from which the winding drum shafts project is supported by rollers (not shown) placed on the foundation of the machine, while the opposite end is supported by a bearing 5 incorporated in the casing 4 of a gearing 3 placed on the front side, so that the body is rotatable. The drum shaft 1a is connected to an electric motor 11a for driving the shaft via a toothed wheel 6a integral with the shaft 1a, a solid, intermediate shaft 7a, a toothed wheel 8a on the shaft 7a mating with the wheel 6a, a toothed wheel 9a on the shaft 7a and in the gearing 3, and a toothed wheel 10a mating with the wheel 9a. The shaft 7a is rotatably mounted in the body 2 and to the casing 4. The other drum shaft 1b is connected to another electric motor 11b for driving it via a toothed wheel 6b integral with the shaft 1b, a toothed wheel 8b mating with the wheel 6b on which the hollow, intermediate shaft 7b, a toothed wheel 8b is mounted, a toothed wheel 9b on shaft 7b and in the gearing 3, and a toothed wheel 10b mating with the wheel 9b. The shaft 7b is rotatably mounted in the body 2. The outer periphery of the body 2 is provided with teeth 12 with which a toothed wheel (not shown) coupled to an electric motor (not shown) is engaged for revolving the body in a circle mate. Thus, when this motor is operated, the body 2 of the machine is rotated. The drum shaft 1a is driven by the motor 11a via the wheels 10a and 9a, the intermediate shaft 7a, and the wheels 8a and 6a. Similarly, the drum shaft 1b is driven by the motor 11b via the wheels 10b and 9b, the intermediate shaft 7b, and the wheels 8b and 6b.
In the driving system of the winding drum shafts 1a and 1b of the above multi-drum coiler or un-coiler, the two sets of toothed wheels, i.e., 6a, 8a and 6b and 8b, are disposed in parallel relation to each other, as described previously, and hence it is impossible to obtain a high reduction ratio. Therefore, it is necessary to achieve the desired reduction ratio by means of the gears within the gearing 3, thus usually making the gearing 3 bulky. Further, since the hollow, intermediate shafts 7a ; and 7b are disposed coaxially, the gearing 3 on the front side is needed independently of the reduction ratio. This coaxial arrangement also makes it difficult to mount, disassemble, check, and maintain the intermediate shafts 7a and 7b. In addition, since the shafts 7a and 7b are arranged to occupy a considerable length, they are difficult to machine. Particularly, the intermediate shaft 7b is difficult to machine, thus requiring a sophisticated machining technique.